How to model a bee's segmented abdomen
You can use edge creases to sharpen edges when using the subdivision surface modifier, and simple bevelling and scaling to generate this effect.

Start with a subdivided capsule with a topology like this:



Select an edge where you'd like to create a segment in the bee's abdomen:



Bevel the edge using the shortcut CtrlB, then move the cursor slightly to create a small bevel.



Select the rear edge.



Scale it down.



Select the front edge, open the options panel with the shortcut N, then crank up the crease to around 0.75.



Finally, you can play with the scale and position of the edges of each segment, and repeat this process to create the segmented abdomen.